Abstract: An early warning tornado detector is provided. The detector utilizes a plurality of horizontally rotatable negative ion flow meters, each of said meters capable of taking measurements of negative ion flow in a linear direction. Means for recording said measurements are provided, as are means for determining the negative ion flow intensity for a fixed location by correlating the linear measurements corresponding to that location taken from at least two of said meters. Also provided is a method for early detection and tracking of meteorological conditions conducive to tornado formation in a given area. In this method the negative ion flow intensity threshold level which indicates that meteorological conditions are conducive to tornado formation in the area is first determined. Then, the negative ion flow intensity over the area is measured. By comparing the measured ion flow intensity with the threshold intensity, it can be determined if tornado formation is imminent.